TY - JOUR A1 - Kranzmann, Axel A1 - Neddemeyer, Torsten A1 - Ruhl, Aki Sebastian A1 - Hünert, Daniela A1 - Bettge, Dirk A1 - Oder, Gabriele A1 - Saliwan Neumann, Romeo T1 - The challenge in understanding the corrosion mechanisms under oxyfuel combustion conditions N2 - Basic research on the corrosive effect of flue gases has been performed at the BAM Federal Institute for Materials Research and Testing (Germany). Conditions at both high and low temperatures were simulated in specially designed experiments. Carburization occured in flue gases with high CO2 content and temperatures higher than 500 °C. In SO2 containing flue gases sulphur was detected in the oxide scale. At lower temperatures no corrosion was observed when gases with low humidity were investigated. Humidity higher than 1500 ppm was corrosive and all steels with Cr contents lower than 12% revealed corroded surfaces. At low temperatures below 10 °C a mixture of sulphuric and nitric acid condensed on metal surfaces. Acid condensation caused severe corrosion. Humidity, CO2, O2, and SO2 contents are the important factors determining corrosion. Below 300 °C acid condensation is the primary reason for corrosion. Low humidity and low temperatures are conditions which can be expected in the CO2 separation and treatment process. This work includes major conditions of the flue gas and CO2 stream in CCS plants and CCS technology. KW - Coal KW - Oxyfuel power plant KW - Corrosion KW - Carburization KW - Sulphur KW - Sulphuric acid PY - 2011 U6 - https://doi.org/10.1016/j.ijggc.2011.05.029 SN - 1750-5836 VL - 5 IS - Supplement 1 SP - S168 EP - S178 PB - Elsevier CY - New York, NY [u.a.] AN - OPUS4-24705 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Krause, S. A1 - Moelders, Theodor A1 - Neidel, A. A1 - Oder, Gabriele A1 - Völker, J. T1 - Influence of heat treatment on microstructure and hot crack susceptibility of laser-drilled turbine blades made from René 80 N2 - Turbine components from conventionally cast nickel-base alloy René 80 show different hot cracking susceptibilities depending on their heat treatment conditions leading to slightly different microstructures. Electron probe micro-analysis, focused ion beam technique and analytical transmission electron microscopy were applied to reveal and identify grain boundary precipitates and the γ–γ'-microstructure. The distribution of borides along grain boundaries was evaluated statistically by quantitative metallography. The following features could be correlated with an increase of cracking susceptibility: i) Increasing grain size, ii) increasing fraction of grain boundaries with densely spaced borides, iii) lack of secondary γ'-particles in matrix channels between the coarse cuboidal γ'-precipitates. The latter feature seems to be responsible for linking-up of cracked grain boundary precipitates which occurred as an additional cracking mechanism after one heat treatment, whereas decohesion at the boride-matrix-interface in the heat affected zone of laser-drilled holes was observed for both heat treatments. KW - Turbine blades KW - Nickel-base superalloy KW - Laser drilling KW - Hotcrack susceptibility KW - Grain boundary precipitates PY - 2008 U6 - https://doi.org/10.1016/j.matchar.2008.01.021 SN - 1044-5803 SN - 1873-4189 VL - 59 IS - 11 SP - 1564 EP - 1571 PB - Elsevier CY - New York, NY AN - OPUS4-17932 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hünert, Daniela A1 - Schulz, Wencke A1 - Nitschke, Heike A1 - Saliwan Neumann, Romeo A1 - Oder, Gabriele A1 - Kranzmann, Axel T1 - Corrosion behaviour of ferritic and martensitic power plant steels under conditions of dual atmospheres N2 - The most efficient construction materials for boiler water walls and superheaters in steam power plants are ferritic and martensitic steels. In practical operation tubes are simultaneously exposed to combustion gas and air/steam on their opposite surfaces. The corrosion behaviour of ferritic-martensitic steels under such dual atmospheres is nondistinctive and has therefore been investigated in a special designed test equipment between 500 and 620°C. The power plant conditions were simulated wi th a flowing and pressurised (80 bar) combustion gas on the inner side of the tube which mainly consists of H2O and/or CO2. On the outer side, the tube material was exposed to air. It was discovered that under similar temperatures the oxides formed on the air side under dual atmosphere conditions were significantly different to the oxide scales formed when the alloy was exposed to air only. It is assumed that the anomalous corrosion behaviour during the dual atmosphere exposure is due to the hydrogen transport through the bulk alloy from the combustion gas side to the air side. T2 - NACE International corrosion conference 2009 CY - Atlanta, Georgia, USA DA - 2009-03-22 KW - High temperature corrosion KW - Dual atmosphere KW - Corrosive gases KW - Mild steels KW - 9-12% Cr-steels KW - Hydrogen transport PY - 2009 SP - 1 EP - 10 (Paper 09263) AN - OPUS4-22335 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rabe, Torsten A1 - Glitzky, Carsten A1 - Naghib Zadeh, Hamid A1 - Oder, Gabriele A1 - Eberstein, M. A1 - Töpfer, J. T1 - Silver in LTCC - Interfacial reactions, transport processes and influence on properties of ceramics T2 - 2009 IMAPS/ACerS - 5th International Conference and Exhibition on Ceramic Interconnect and Ceramic Microsystems Technologies (CICMT) CY - Denver, Colorado, USA DA - 2009-04-21 KW - LTCC KW - Silver conductors KW - Interface KW - Sintering KW - Ferrite KW - Capacitor PY - 2009 SN - 0-930815-87-4 SP - 000085 EP - 000093 AN - OPUS4-19428 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Epishin, A. I. A1 - Link, T. A1 - Nolze, Gert A1 - Svetlov, I. L. A1 - Bokshtein, B. S. A1 - Rodin, A. O. A1 - Saliwan Neumann, Romeo A1 - Oder, Gabriele T1 - Diffusion processes in multicomponent nickel-base superalloy-nickel system N2 - Optical and scanning electron microscopy, as well as electron microprobe analysis and electron backscatter diffraction, have been used to study diffusion processes that occur in a diffusion pair that consistsof a single-crystal CMSX-10 nickel-base superalloy and polycrystalline nickel, at temperatures of 1050–1250°C. It has been found that, in this system, the distributions of γ-stabilizing elements (Cr, Co, W, and Re) are described by the Boltzmann solution for diffusion between two semiinfinite plates of a binary alloy. The processing of these distributions has shown that the diffusion coefficients of Cr, Co, W, and Re in the multicomponent system are close to those in binary alloys of these elements with Ni. The diffusion redistribution of the elements leads to the dissolution of the γ′ phase in the nickel-base superalloy, growth of nickel grains toward the superalloy constituent of the diffusion pair, and the formation of porosity on both sides of the migrating interface, which is determined from a crystal misorientation of the alloy single crystal and nickel grains. KW - Ni-base superalloy KW - Interface KW - Diffusion KW - Phase transformation KW - Porosity PY - 2014 SN - 0031-918X VL - 115 IS - 1 SP - 21 EP - 29 AN - OPUS4-37980 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chandra, Kamlesh A1 - Kranzmann, Axel A1 - Saliwan Neumann, Romeo A1 - Oder, Gabriele A1 - Rizzo, F. T1 - High temperature oxidation behavior of 9-12 % Cr ferritic/martensitic steels in a simulated dry oxyfuel environment N2 - The materials in oxyfuel power plant will be subjected to CO2– and SO2–rich gases on the fireside. The oxidation behaviour of two 9–12 % Cr steels T92 and VM12 was studied under dry oxyfuel environment in the temperature range of 580–650 °C for up to 1,000 h. The oxide structure and morphology were analyzed using various experimental techniques. A complex temperature dependence of oxidation rate is observed for both T92 and VM12 whereby the oxidation rate decreased with increasing temperature. This is attributed to increased Cr-enrichment in the inner scale with increasing temperature. T92 and VM12 alloys are also susceptible to carburization in an oxyfuel environment. KW - Oxyfuel environment KW - Ferritic/martensitic steel KW - Oxidation KW - High temperature corrosion KW - Carburization KW - Steel KW - EPMA KW - SEM PY - 2015 U6 - https://doi.org/10.1007/s11085-014-9521-4 SN - 0030-770X SN - 1573-4889 VL - 83 IS - 3-4 SP - 291 EP - 316 PB - Springer CY - New York, NY AN - OPUS4-32737 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Naghib-zadeh, H. A1 - Oder, Gabriele A1 - Hesse, J. A1 - Reimann, T. A1 - Töpfer, J. A1 - Rabe, Torsten T1 - Effect of oxygen partial pressure on co-firing behavior and magnetic properties of LTCC modules with integrated NiCuZn ferrite layers N2 - Low-κ dielectric LTCC was developed, to realize successful co-firing with NiCuZn ferrite tapes. A critical high-temperature process in the production of highly integrated LTCC modules is the migration of silver from inner conductors into the LTCC glass phase. Intensive silver migration causes strong deformation of LTCC multilayers during firing in air. Silver migration into the LTCC glass phase depends on oxygen content of the sintering atmosphere and can be minimized by sintering in nitrogen atmosphere. However, partial decomposition of NiCuZn-ferrite and formation of cuprite was observed during sintering in nitrogen and, consequently, the permeability of the ferrite decreases. As shown by a combined XRD/thermogravimetric study the co-firing of LTCC modules with silver metallization and integrated ferrite layer demands precise adjustment of oxygen partial pressure. KW - Ferrite KW - Silver diffusion KW - Co-firing KW - LTCC PY - 2016 U6 - https://doi.org/10.1007/s10832-016-0043-0 SN - 1385-3449 SN - 1573-8663 VL - 37 IS - 1-4 SP - 100 EP - 109 PB - Springer Science+Business Media CY - New York AN - OPUS4-38603 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schempp, Philipp A1 - Cross, C.E. A1 - Pittner, Andreas A1 - Oder, Gabriele A1 - Neumann, R.S. A1 - Rooch, Heidemarie A1 - Dörfel, Ilona A1 - Österle, Werner A1 - Rethmeier, Michael T1 - Solidification of GTA aluminium weld metal: Part I - Grain morphology dependent upon alloy composition and grain refiner content KW - Aluminium KW - Gas tungsten arc welding (GTAW) KW - Grain refinement KW - Columnar to equiaxed transition (CET) KW - Epitaxial nucleation KW - Duplex nucleation theory PY - 2014 SN - 0043-2296 SN - 0096-7629 VL - 93 SP - 53-s - 59-s PB - American Welding Society CY - New York, NY AN - OPUS4-30413 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mosquera Feijoo, Maria A1 - Oder, Gabriele A1 - Saliwan Neumann, Romeo A1 - Buchheim, Michaela A1 - Kranzmann, Axel A1 - Olbricht, Jürgen T1 - Impact of Sample Geometry and Surface Finish on VM12‑SHC Ferritic–Martensitic Steel Under Cyclic Steam Atmosphere Operating Conditions N2 - The steam side oxidation of ferritic–martensitic VM12-SHC steel was investigated under thermo-cyclic conditions in water steam at 620/320 °C and 30 bar with a focus on assessing the influence of pre-oxidation time, specimen geometry and surface finish. The specimens were pre-oxidized under isothermal conditions in water steam at 620 °C and 30 bar for 500 h or 1500 h. After pre-oxidation treatment, all specimens were subjected up to 258 thermal cycles. Three different geometries—rectangular coupons, U-shaped ring segments and ring samples—were investigated to evaluate the influence of open/closed shape, and flat/curved surface on corrosion rate. At the same time, two types of surface finish were considered: “as received” and “ground.” The formation of a protective scale by pre-oxidation was investigated. EBSD and ESMA analyses revealed that the Cr-content of the alloy appeared to be insufficient for obtaining a protective oxide scale under studied conditions, at the same time the anayses confirmed that initial oxidation depends on presence of minor alloying elements as Si and Mn, strong oxide formers which can alter the kinetics and morphology of the corrosion reaction. Moreover, rectangular coupons with small wall thickness and flat surface exhibited the highest corrosion rate, while “ground” curved samples showed only local oxidation. This indicates that for same pre-oxidation time, oxidation kinetics is controlled by curvature. KW - Cyclic steam oxidation KW - 12%Cr steel KW - Specimen geometry KW - Surface treatments PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-551808 SN - 0030-770X SP - 1 EP - 18 PB - Springer AN - OPUS4-55180 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lemiasheuski, Anton A1 - Bajer, Evgenia A1 - Oder, Gabriele A1 - Göbel, Artur A1 - Hesse, Rene A1 - Pfennig, A. A1 - Bettge, Dirk T1 - Entwicklung eines automatisierten 3D-Metallographie-Systems und erste Beispiele für die Anwendung in der Gefüge-Analyse T1 - Development of an automated 3D metallography system and some first application examples in microstructural analysis N2 - Die klassische Metallographie basiert auf Abbildungen einzelner Schliffebenen und kann auf räumliche Formen und Anordnungen des Gefüges nur bedingt schließen. Die Idee, aus metallographischen Serienschliffen dreidimensionale Gefügestrukturen zu rekonstruieren, ist daher naheliegend und nicht neu. Allerdings ist der Aufwand, in Handarbeit viele Einzel-Schliffe zu präparieren und zu Bildstapeln zusammenzusetzen, sehr hoch und steht einer häufigen Anwendung entgegen. Deshalb wird an der BAM ein Roboter-gestütztes 3D-Metallographie-System entwickelt, das an einer Schliffprobe die Schritte Präparation und Bildeinzug vollautomatisch mit vielen Wiederholungen ausführt. Die Präparation umfasst Schleifen, Polieren und optional Ätzen der Schlifffläche, der Bildeinzug autofokussierte lichtmikroskopische Aufnahmen bei mehreren Vergrößerungsstufen. Der erhaltene Bildstapel wird anschließend vorverarbeitet, segmentiert und in ein 3D-Modell umgesetzt, das einer mikrotomographischen Aufnahme ähnelt, allerdings mit besserer lateraler Auflösung bei großem Volumen. Im Gegensatz zu tomographischen Verfahren besteht die Möglichkeit der Kontrastierung durch klassische chemische Ätzung. Die Integration eines REMs ist geplant. Bislang durchgeführte Arbeiten verdeutlichen die Möglichkeiten der Darstellung von Heißgas-Korrosionsschichten, Grauguss-Werkstoffen und Keramik-basierten mikroelektronischen Strukturen (Vias). N2 - Traditional metallography relies on the imaging of individual section planes. However, conclusions as to spatial shapes and microstructural arrangements can only be drawn to a limited extent. The idea to reconstruct three-dimensional microstructures from metallographic serial sections is therefore obvious and not at all new. However, the manual process of preparing a great number of individual sections and assembling them into image stacks is time-consuming and laborious and therefore constitutes an obstacle to frequent use. This is why the Federal Institute for Materials Research and Testing, or BAM for short (Bundesanstalt für Materialforschung und -prüfung), is developing a robot-assisted 3D metallography system performing the tasks of preparation and image acquisition on a metallographic section fully automatically and repeatedly. Preparation includes grinding, polishing and optional etching of the section surface. Image acquisition is performed using a light optical microscope with autofocus at several magnification levels. The obtained image stack is then pre-processed, segmented and converted to a 3D model resembling a microtomographic image, but with a higher lateral resolution when large volumes are sampled. As opposed to tomographic techniques, it is possible to perform traditional chemical etching for contrasting. The integration of a SEM is in the planning stages. Studies conducted so far have demonstrated the possibility of visualizing hot gas corrosion layers, grey cast irons and ceramic-based microelectronic structures (vias). KW - 3D-Metallographie KW - Gefügeanalyse KW - Serienschnitte KW - Gefügerekonstruktion KW - 3D metallography KW - Microstructure analysis KW - Serial sectioning KW - Microstrucure reconstruction PY - 2023 U6 - https://doi.org/10.1515/pm-2023-0057 SN - 0032-678X VL - 60 IS - 10 SP - 676 EP - 691 PB - De Gruyter CY - Berlin/Boston AN - OPUS4-58593 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -